American Horse Fly

The American Horse Fly is known as Tabanus americanus, and is between 3/4-1 1/8" (20-28mm) long. They have a large, broad body, their head is tan to ash-gray between their large green eyes. The American Horse Fly has reddish brown antennae, a brownish to black thorax with gray hair, and an abdomen that is blackish red-brown. Their wings are a smoky brown to black near the base.

• The male eats pollen and nectar while the female takes blood of large mammals. Larvae preys on aquatic insects and other small animals.
• Egg masses are attached to plants overhanging fresh water, into which larvae drop. Larvae stay in the muddy bottom and they pupate in spring. Males are short-lived, but females may survive until fall.
• The like to live mostly near swamps, marshes, and ponds.
• Range Newfoundland to Florida, west to Texas and northern Mexico, north to Canadian Northwest Territories.
• Warning When the female bites, the wound inflicted often continues to bleed for several minutes because the fly's saliva contains an anticoagulant that prevents clotting. A single animal may suffer a debilitating loss of blood if many of these insects attack it.

Black Fly

The Black Fly is also known as the Family Simuliidae, which contains 166 species in North America. They are between 1/16-1/8" (2-4 mm) in length, have a humpbacked, downward pointing head, thick antennae with many segments, smoky heavy veinged wings, and are grayish brown to shiny black in color.

• Both the male and female feed on nectar. The female sucks blood from birds and mammals. Larvae are filter feeders, eating particles such as diatoms and bacteria.
• Eggs are laid on stones or leaves at the edge of rapidly flowing streams, or on the water surface itself. Larvae tumble into water. Fully grown larvae pupate in cocoons that coat rocks in water, resembling moss. Adults burst out, rise on a bubble of trapped air, and fly away in late spring and early summer.
• Black flys can be found near running water in forests, mountains, and tundra, from Labrador south to Georgia, west to California and Mexico, north to Alaska.
• Biting adults are the bane of the North Country and mountain resorts, particularly early in the season. Some species transmit waterfowl malaria, which accounts for up to half of the deaths of ducks, geese, swans, and turkeys.
• Warning: Female sucks blood from birds and mammals. Not known to transmit diseases to humans in North America.

Blow Fly

The Blow Fly is also known as the family Calliphoridae. The adult is a robust tawny fly averaging 9-12mm long, although undersized specimens are frequently seen. The eyes of the female are separated by about 1-2mm, whereas on the male they adjoin one another. Adults can be seen at all times of the year, but are most common in spring, summer, and autumn.

• The eggs, which are laid in small clusters, are creamy white and about 1mm long. The young larvae (maggots) are grayish-white and segmented. There are three instars (larval stages), and the fully grown maggot may be 12-15mm long. The reddish-brown, barrel-shaped pupae can be found a few centimeters below the surface of the ground.
• Hosts: The larvae of these flies are normally found on carrion, but the female fly will sometimes lay her eggs or larvae on the fleece of live sheep. A sheep or ox carcass will support many thousands of larvae.
• Damage: The blowflies cause little damage, as they are normally scavengers that are the first in a chain of insects that clean up carcasses. However, when they attack a living animal (usually a sheep), severe damage or death of the animal may occur. The female fly is attracted to sheep when the wool is wet or damp. The odor of feces, urine, or bacterial straining will also attract flies. The adult fly is a nuisance in households or shops where fresh or uncooked meat is present, and unprotected meats are likely to be fly struck (have eggs laid on them). Adults are also attracted by the Odor of some vegetables, such as cooked cabbage. Females are usually looking for a protein meal pa prerequisite for egg production) or somewhere to lay their eggs or larvae.
• Distribution: The brown blowfly is a native of Australia, and has been known in New Zealand since the beginning of European colonization. It is found throughout the country, from sea level to above the bush line. It is closely related and very similar in appearance to another species of blowfly commonly found in forest areas.
• The adult female is viviparous (gives birth to larvae) in the warm summer months, but in cooler weather lays eggs. When eggs are laid, they hatch in a few hours, and the larvae reach full size and stop feeding after about 3-4 days. The fully grown larvae migrates away from the food source, and burrows underground a few centimeters to pupate. Pupation takes 2-3 days, and the pupae stage lasts a further 8-10 days. Flies are not sexually mature until several days after emergence, and after mating the female will then commence depositing up to about 200 live larvae or eggs on a suitable substrate, over a period of 2-3 weeks. Depending on ambient temperature, female flies may live for several weeks after egg laying is complete. The entire life cycle from egg to egg takes 3-5 weeks during summer, but considerably longer in the winter months. Pupae are known to over winter in the soil, and it seems likely that larvae could do the same, as this is known to occur in other species. When ready to emerge, the young adult forces its way out of the end of the pupae case, finds its way to the surface of the ground, and expands its wings, which soon harden off. Females fly off in search of a protein source. Little is known about the male but it probably lives as long as the female, and once it has fertilized one female, will probably seek others. Adult flies will shelter in trees and buildings during winter, occasionally flying on warm, sunny days, but rarely laying eggs. Four to five generations a year can be expected.

Cluster Fly

Cluster flies, Pollenia rudis, are close relatives of blow flies and are similar in size to house flies (3/8-inch) but are more robust in body structure. They are nonmetallic gray, lack stripes on the thorax (segments with the wings and legs attached), and have yellow or golden hairs on the back, behind the head, and around the base of the wings. Cluster flies appear narrow when at rest because their wings completely overlap over their backs. The larvae are typical spindle-shaped maggots but are never seen because they develop as parasites in earthworms.

• Biology: The female flies mate in the spring and lay their eggs in soil crevices. The eggs hatch in three days and the larvae burrow into the bodies of earthworms where they develop. Development (egg to adult) requires 27 to 39 days. There are usually four generations per year.
• Habits: Cluster flies are annoying because they over winter as adults in the attics and wall voids of structures, especially older frame buildings. The common name of this species reflects its behavior of gathering in clusters before hibernation. They enter structures in early fall to seek shelter from cooling temperatures. Soon, a "cluster" of adult flies accumulates in wall voids and dark corners, under shelving, beneath curtains, and in other protected areas.
  On warm days in winter and spring, they annoy building occupants when they become active and crawl sluggishly over walls or windows. When the weather warms, the cluster flies emerge from their hiding places and either exit the building or enter interior areas. They are stimulated by warmth and are often found on the south and west sides of buildings. Once stimulated, cluster flies are attracted to light.
• Control: There is no effective control of the larval stage of these flies because they develop in earthworms. Control tactics for cluster flies should be initiated before they enter buildings in large numbers. The most effective long-term control in structures attractive to overwintering adults is to seal entry points in the walls and roof of the structure. To prevent entry into interior rooms, entry routes, e.g., around window pulleys, electrical outlets, switch boxes, and window and door frames should be sealed. Large accumulations of these flies can be removed with a vacuum cleaner.
  During the winter, a bare light bulb in an attic will cause the flies to die from cold exposure and exhaustion of their food reserves. Insect light traps can also be placed in attics but require frequent servicing.
  Cluster flies can not be controlled by disrupting the life cycle of the larvae (maggots) because they are parasitic on earthworms which are beneficial contributors to the environment. Residual applications of micro-encapsulated and wettable powder formulations should be applied in the fall to the exterior surfaces of structures in order to control these flies prior to entry.

House Fly

The House fly, known as Musca domestica, is 1/8-1/4" (3-6 mm) in length, has gray with 4 black lengthwise stripes on thorax, gray or yellow on abdomen with a dark midline and irregular dark markings on sides, reddish eyes, and slightly feathery antennal bristle (arista). The housefly's legs are hairy, each tarsus has adhesive pads and sharp claws, the mouthparts expand at end, and are suitable for sponging up food. It's wings are clear, and are held level and straight back.

• Food Adult sucks liquids containing sweet or decaying substances. Larva feeds on moist food rich in organic matter.
• Life Cycle Female lays 5-6 batches of 75-120 oval, white eggs on moist manure or garbage. Eggs hatch in 10-24 hours. Larvae reach full size in 5 days emerging as adults about 5 days later. Males live for 15 days, females up to 26 if they have access to milk, sugar, and water.
• Habitat Near horse manure, garbage, or exposed food.
• Range Worldwide, except in Antarctica and a few remote islands.
• Discussion 98 percent or more of the flies caught in houses are House Flies. Because they can transmit typhoid fever, cholera, dysentery, pinworms, hookworms, and some tapeworms, House Flies are regarded as a greater threat to human health than most other insects. The larger and darker Face Fly (M. autumnalis), 1/4-3/8" (6-8 mm), resembles the House Fly but settles on cow rather than horse manure. It creeps into the nostrils and eyes of cattle and into horse fly wounds.